The invention relates to a procedure and to a device for the detection of extraordinary events in a series of essentially periodically recurring normal events, particularly extra systoles in the EKG, whereby upon each occurrence of a normal event a monitoring interval starts and is examined to determine whether further events, which are evaluated as extraordinary, occur with this monitoring interval; and whereby the monitoring interval can be optionally set at a constant value or at a value that is variable concomitant dependent upon the time interval between specific normal events that succeed one another periodically.
When switching over from a constant value to the variably concomitant value of the monitoring interval there arises the exigency that after each switching-over operation the concomitant monitoring interval must be set anew in percentages of the momentary interval of normal events (for example R-tooth intervals in the EKG). This operation is time-consuming and troublesome, as long as it must be undertaken manually.